This invention relates to the production of continuous glass fibers, e.g., fibers made by melting particulate batch ingredients or minerals, including basalt and the like, and, more particularly, to a method of and apparatus for controlling the breakage of glass fibers during the fiber forming process.
It is well known in the art that continuous glass fibers can be produced by attenuating a plurality of streams of molten glass into fibers, collecting the fibers into a strand and winding the strand into a package for subsequent use in manufacturing various products. The molten glass flows from a furnace, through a forehearth, into a feeder or bushing which has a plurality of orifices formed therein. The molten glass flows from the orifices as streams which are pulled downwardly at a high rate of speed for attenuation into fibers. A plurality of the attenuated fibers are then gathered together into a strand, coated with a sizing and wound onto a collection tube on a winder collet.
One of the major problems in the production of continuous fibers from bushings having tipless orifice plates, such as the bushings disclosed in Strickland, U.S. Pat. No. 3,905,790, is the tendency of the plate to completely flood with molten glass whenever the process is interrupted. If a tipless orifice plate becomes flooded, it will not clear itself or achieve filament separation to allow a restart of the process without the application of considerable time and effort by an operator skilled in the technique. Generally, the length of time required to restart a tipless bushing process is proportional to the unattended hanging time of the bushing after a break. Early detection of a break by the operator allows him to maintain filament separation and restart the process before a major flood can develop.
Therefore, it is an object of the present invention to provide a method of and apparatus for controlling the flooding that occurs on a bushing when a break occurs in the fibers break during the attenuation process.